Car wheel lubricant composition in solid stick form



CAR WHEEL LUBRICANT coMPosmoN IN soun STICK FORM Joseph F. May, 5938 Enright Ave., St. Louis, M0. N Drawing. Filed Jan. 12, 1956, Ser. No. 558,608 1 Claim. (Cl. 252-30) This invention is for an improved car wheel flange lubricant stick and is an improvement over Patent No. 2,589,582, granted to me and Peter Strughold on March 18, 1952.

Among the aims of this invention are to provide a lubricant stick better able to withstand impact and shock under hard service; a stick having increased weather resisting ability; increased heat resisting qualities; a stick which is less expensive to produce; and which provides greatly increased adhesive or clinging ability of the dry lubricant to the wheel flange to which it is applied.

This application is a continuation-in-part of my copending application, Serial No. 347,401, filed April 7, 1953, for Dry Lubricant Stick for Wheel Flanges, now abandoned.

As has been outlined in Patent No. 2,589,582 (mentioned above), it has long been recognized by railroad operating personnel that grease and oils for lubricating wheel flanges have the practical disadvantages of picking up and holding sand and other abrasives against the wheel. Therefore, a dry lubricant which will refuse to hold the sand or other abrasives and yet give the desired lubrication is an important advance in the art. I have discovered that graphite, a relatively inexpensive dry type lubricant when properly held captive in a solid, preferably stick form, for ease and convenience of application and barely sutficiently hard to avoid excessive disintegration, is ideal. I have also discovered that an ideal composition for a car wheel flange dry lubricant stick, to have all the desirable enumerated qualities is to make such stick of a compound of phenol, formaldehyde, household ammonia, graphite, plus reacted sulphur.

The phenol and formaldehyde together with the ammonia as a catalyst react to form a synthetic condensation product which is hard, insoluble and infusible. It is thermosetting and the sulphur substantially accelerates the thermosetting of the compound to be molded, hence it is less expensive to produce for railroad use. Since sulphur melts at 230 degrees Fahrenheit, by subjectingthe aforementioned compound to a minimum of 250 degrees Fahrenheit, the intense internal heat caused by the reaction of sulphur on phenol in the presence of pressure causes the compound to become plastic more rapidly, so as to ordinarily require a pressure of not more than 2,000 pounds per square inch to form a lubricating stick of my invention when composed of 85% dry lubricant (graphite), 5% reacted sulphur, and of formaldehyde and phenol together, in which latter the proportions are from 5% to 10% of formaldehyde and from 90% to 95% of phenol, or equivalents.

The formaldehyde and phenol product acts as a binder for the lubricant. The sulphur imparts additional strength to this binder so that the dry lubricant can be increased to compose 97% of the stick.

But, mostly, by recognizing and the novel use of sulphurs peculiar sensitivity to frictional disturbance, the stick is compelled to impart itself as a thicker, more adhering, more slippery lubricating film on the wheel flange.

* Unit Sttes Patent 0 2,970,109 Patented Jan. 31, 1961 2 Hence, when this lubricating stick is held in forcible contact with the revolving car wheel flange, the friction could compel the sulphur to act several ways to force this heavier film.

First, the friction causes the sulphur to electrolyze or decompose the binder at the contact point of the lubricating stick and revolving wheel, thus releasing the captive dry graphite for lubrication. Secondly, the frictional heat stimulates the sulphur into forming an oxidizing film as a beneficial lubricant to keep metal surfaces separate. Thirdly, friction causes sulphur to become negatively charged and sets up a polar attraction to hold the dry lubricant on the car wheel flange.

v The increased slipperiness could be stimulated by the improved elastic property and low shear strength of the sulphur film.

The coaction of sulphur with formaldehyde, phenol, ammonia, and graphite under heat and pressure, in forming my lubricant stick, results in what I call reacted sulphur in this compound. The synthetic condensation product resulting from my formula is comparatively less hard than conventional products of such nature made from reaction of formalydehyde on phenol due to the very small amount of formaldehyde used in proportion to the phenol. By reason thereof, the product is an ideal binder for the graphite or other dry lubricant and only a small proportion of the binder is required to sufliciently hold the large amount of the lubricant.

The lubricant has been referred to as graphite but for my purposes this term includes talc, soapstone, plumbago or amorphous graphite, or equivalents, either singly or in combination and reference herein to graphite will be so understood.

My stick is sufliciently strong and long lasting to require only a simple means of holding it and bringing it, when desired, into contact with the car wheel or car wheel flange.

Although I am unaware of the exact action or reasons for the same, free sulphur will not result from the use of my stick and my surmise is that some chemical combination or reaction has taken place in my compound which in some way eliminates the presence of free sulphur.

In general, my lubricating stick is formed as follows:

The catalyst is household ammonia and the amount is in the proportion of /2% of the compound.

The dry lubricant and sulphur are thoroughly mixed in powdered or granular form and combined with the previously mixed liquid binder and catalyst to form a dough which is molded under pressure of at'least 2,000 pounds per square inch for a period of at least one hour at 250 degrees Fahrenheit to form a generally serviceable lubricating stick. If additional heat curing is desired, baking the stick for one to four hours at 300 to 350 degrees Fahrenheit is all that is needed. However, where the dry lubricant is or more and the binder, catalyst and reacted sulphur form only 10% or less, it has been found advantageous to a better mix to thoroughly intermix the liquid binder and catalyst, direct with the dry lubricant and dry sulphur and with just sufiicient heat and pressure to preform it into a rough unfinished lubricating stick. This stick is then placed in a regular finishing mold with suflicient heat and pressure to form the cured finished lubricating stick. Generally the less the amount of hinder the more readily will the lubricant stick be able to impart itself as a beneficial lubricating film on the wheel flange.

Where dielectric heating is available the reduction in the curing time is comparable to that in the molding art generally.

This improved for of lubricating stick would be relatively stronger, more weather resistant than sticks formed of the conventional Bakelite binder, and would also be more capable of providing a more clinging dry lubrication film to an alreadyy badly worn crystalized, smooth, nouporous flange to prevent further undue wear and to minimize the tendency of metal seizure or galling between the flange and rail head.

I do not mean to confine myself to the exact details of construction herein disclosed, but claim all variations falling within the purview of the appended claim.

What I claim is:

A car wheel lubricating composition in solid stick form comprising, in combination, 80% to 95% of graphite, 693% to 2 /2% of sulphur, and 13%% to 216% of a phenol formaldehyde binder wherein the phenol to formaldehyde ratio is 90% to 95% to 10% to 5%, which has been formed by the thorough admixture of the graphite and sulphur in powdered form and the subsequent addition of the binder admixed with an ammonia catalyst in liquid form to produce a dough which is then solidified under heat and pressure.

References Cited in the file of this patent UNITED STATES PATENTS 

